Today, a new look at the birch-bark canoe. The University
of Houston's College of Engineering presents this series
about the machines that make our civilization run, and
the people whose ingenuity created them.

No really clever invention gets
very far in its original form. It goes through changes
until it either catches on or dies out. Every now and
then, an idea doesn't just catch on. People improve it
until it fits its purpose perfectly -- until it can't be
changed any more. And that's how it was with Indian
canoes.

When I was a kid in Minnesota we called ourselves the
"Land of 10,000 Lakes." That wasn't just for the
tourists. The place is riddled with lakes, and they all
have canoes on them. Nowadays most canoes are made of
aluminum or fiberglas, with polystyrene floats in the bow
and stern. But they're still very nearly carbon copies of
the old Indian birch-bark canoe.

Historians have traced the Indian canoe back as far as
they can, but that's not very far. Indians didn't keep
much in the way of written records. The canoes themselves
were completely biodegradable, so we don't have
archeological remains, either. All we do have are some
scanty records left by European explorers after the 16th
century. All we really know is that canoe-making was
perfected a long time ago and that it stayed static for
centuries.

Canoes are shallow-draft boats with a fine, delicate
shape. Their perfect hydrodynamic form has a lot in
common with the Viking ship. One advantage over a rowboat
is that the paddler faces the direction he's going. Most
Indian canoes were small, light, and fast. They'd carry a
few people rapidly up and down rivers and lakes. The
Iroquois built big, 30-foot-long freight-carrying canoes
that could haul 18 passengers or a ton of merchandise.
But even they could be portaged by just three people.

The Indian canoe was a tough light wooden frame with a
skin of bark -- usually birch. Sometimes the bark was put
on in one piece and pleated to take up slack as it was
contoured. Sometimes it was sewn in sections and caulked
with spruce gum. The techniques of sewing, binding,
carving, and selecting and preparing materials were very
sophisticated. Designs varied from tribe to tribe,
according to local conditions. But even the kayak in the
far north, covered with animal skin instead of bark,
reflects the same concepts of shape and propulsion.

Every now and then human ingenuity brings a technology to
a kind of dead end of functional perfection. That's far
from true of today's computers or telephones. But it is
true of stringed instruments, silverware, and lead
pencils. It's scary to consider that once a technology
gets to this point, further change has to come from
beyond our imagination. The motorboat, after all, came
from some place far outside the dreams of Indian canoe
makers.

I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.